A Perfect Day
by SexyCactus
Summary: Fionna is alone on a perfect day, and wants to spend it with her vampire friend. When she finds him alone in a compromising position, her curiosity gets the better of her. -Lemons ensue-
1. Chapter 1

**Author's note: This is my first fanfic on this site, so I'm not used to the format and whatnot. Sorry if there are any errors, please inform me if there are so I can be aware of them in the future. This is going to be a multi-chapter Fiolee smutfic depending on the positive/negative reactions I get from it. I'm sorry if you read this story and feel as though it is similar to any others you have read. I assure you I've never read a story like it before, and that this is just what I decided would be a fun situation ;)**

**I don't own Adventure Time ;_; although I certainly wish I owned Marshall Lee. -sigh-**

**And with that, let's begin!- Lemons full steam ahead! chuggachuggachoochoo goes the smut-train~**

~0o0~

It was a beautiful day in Aaa; the sun was shining, the birds were chirping, and not a single prince was in need of a saving. It was perfect, almost too perfect. Fionna sat upright on the couch pondering how she would spend her day outside, because let's face it, our little adventuress was feeling, well, adventurous.

"Hey Cake," she chirped, "What do ya wanna do today? Wanna explore the forest or pester the Ice Queen?"

"Nah, baby, I have a date with Monochromicorn, I'm so sorry I forgot to tell you. We'll be out all day. I hate to leave you all by yourself baby sis," replied Cake with a sheepish grin.

"It's alright Cake, I'll figure out something. Have fun and stay safe!"

"Don't worry hun, go visit Prince Gumball and you won't even notice I'm gone."

And with that, Fionna was left to watch Cake's brown and white body disappear into the distance from her perch by the window. Fionna sighed. It would be such a waste of a perfect, non-chaotic day to just sit at home waiting for Cake to return. With a grunt, she trudged down the stairs, grabbing her sword along the way, and out the door, still not entirely sure of where she was headed. Briefly, she glanced toward Prince Gumball's castle in the Candy Kingdom. "Hmm" she thought, "Lately Gumball has been kind of boring, showing off his scientific observations and experiments. Maybe I'll spend my day with someone else." The image of a pale, dark haired vampire flashed through her mind. "I know! I'll pay Marshall a visit! I haven't seen him in weeks! Maybe we can go strawberry picking or watch a movie!" Excited and determined, Fionna headed towards the forest, and most importantly, to Marshall Lee's cave.

~0o0~

Fionna's journey through the forest was surprisingly peaceful. No ogres or monsters dared to attack her. They were all probably enjoying the sunny day as well. As she neared Marshall's cave, she noticed the atmosphere changing quickly. The sky had darkened and clouds had formed over head. Looking over her shoulder, Fionna noticed the skies were still bright and cheery back where she had come from. She had never noticed it before, but it was almost as if this one patch of forest was shrouded in darkness just for the vampire living nearby. Before she knew it, she had reached his humble abode.

"Marshall?" Fionna called, peeking into the entrance. There was no answer. "Marshall Lee? Marshie?" she called more frantically, not wanting to enter his house without permission. She was greeted with a strange noise. It was faint, almost like a sound she would make after tasting a delicious strawberry. "Marshie..are you alright in there..?" Fionna tentatively asked again. The noises were getting louder and more urgent, he was gasping and moaning! He sounded as though he was struggling with an intruder. "Oh my Glob, Marshall's in trouble!" thought Fionna. She quickly whipped out her sword and charged into the house, trying not to make too much noise as to not startle Marshall any further in the midst of chaos.

What she saw shocked her. Nothing in the cave seemed out of place and there was no sign of a struggle anywhere. She stopped and listened. The sounds seemed to be coming from his room. "uhhh….ahhh.." There were those strange noises again! Careful not to make a sound, Fionna tiptoed to his bedroom door which was slightly ajar. "OH. MY. GLOB." she thought, recoiling slightly. There on the bed was Marshall Lee. He was very alone, and very..oh glob. Marshall lay splayed out on the bed with his head thrown back, his lips parted in a silent "oh." His messy black hair was sweaty, his bangs sticking to his forehead in a very sexy manner. Woah, sexy? "What are you thinking Fionna, you need to stop looking. This isn't right! He's your best bud, now stop!" Fionna scolded herself internally. But she couldn't stop. Her eyes were glued to his form as they trailed downward. His red plaid shirt was unbuttoned half way, and his jeans, oh glob, his jeans, ripped at the knees, were unbuttoned, the material of his matching plaid boxers peeking slightly out of the fly. His right hand gripped tightly to what should have been hidden from Fionna's innocent eyes. His fist pumped frantically, his mouth opening and closing emitting small, labored pants. "Oh Fionna," he moaned huskily. Fionna's face paled. "This is it, he's caught me. I'm dead. He's gonna kill me. What have I done?" She recoiled further onto the ground in fear. But nothing happened. "Hnnng.." Another moan. She looked up and saw his eyes were screwed tightly shut. "Wait. He hasn't caught me? But I heard him say my name. Unless..does he have feelings for me?" her mind was reeling.

His noises were causing a strange reaction within her. It was something new, something she had never experienced before. She felt as though butterflies were traveling from her stomach down lower, settling between her legs. Moistness formed, and she was tempted to let her fingers travel lower to relieve the discomfort as she watched Marshall's private, erotic display. Tentatively, she lifted her hand and placed it over her panties under her skirt, rubbing gently. She gasped suddenly, turning away; the feeling was almost too new and intense. She bit her lip holding back a moan. "Uh…ahh..AHH..MMMmm" shouted Marshall suddenly, making Fionna jump, her thoughts scattering. She peeked around the corner to see Marshall tug one last time on his massive erection, before a strange white substance exploded from the glistening tip. "Eek!" Fionna dropped her sword out of shock with a clank. His eyes opened immediately, darting around the room, the peaceful afterglow gone. Pulling up his jeans quickly and haphazardly zipping them up, not bothering with the button, he yelled "Who's there?" and began to float cautiously toward the door. "No no no" whispered Fionna under her breath. She darted to the living room, scampering across the floor before finding a small corner behind the couch to hide and press her face into her hands. She took a deep breath and held still. It was quiet. Too quiet. The hairs on the back of her neck began to stand up, and she felt a hot breath against her skin.

**"Found you." **


	2. Chapter 2

**Author's note: The people have spoken! This will definitely be a multi-chapter fic, and I'll be sure to update a lot this weekend before all my filthy filthy ideas run dry. With that, enjoy!**

**I still don't own Adventure Time :'c **

~0o0~

**"Found you."**

Fionna jumped, her heart stopping for a second. She squeezed her eyes shut, trying not to turn around, some tears forming at the corners of her eyelids. Still not facing him, she forced herself to speak,

"SORRY MARSHALL I JUST GOT HERE I WAS GOING TO ASK YOU IF YOU WANTED TO GO STRAWBERRY PICKING BUT I GUESS YOU'RE BUSY IT'S ALRIGHT MAYBE ANOTHER DAY I HAVE TO GO BYE."

It all came out in a rush of words, her voice cracking in the end. This was too embarrassing for her, and Marshall wasn't saying anything. She assessed her choices. "I could turn around and face him…or I could make a run for it" she pondered. She was only a few paces from the door anyway. Abruptly she stood up, an audible surprised gasp escaping from the vampire behind her. Without even a glance, she sprinted to the door. She was fast, but he was faster, and with just three steps to the door to spare, she collided with a muscular chest, her arms instinctively wrapping around him, knocking them both to the floor with a thud. "Oh glob I'm so sorry Marshall, did I hurt you?" she asked in panic, completely forgetting her embarrassment out of worry. She rolled off of him, her leg brushing the moistened crotch of his jeans in the process. Their eyes met and Fionna's blush mirrored Marshall's. She turned away, standing up and walking toward the door. She was stopped yet again by a hand grabbing her wrist. Then he finally spoke.

"How long have you been here?" It was almost a whisper. His hand dropped. Fionna looked up to see Marshall wasn't looking directly at her, his gaze intent on the fabric of the couch. "N-not long." she muttered, looking down. Her gaze fell on the wet spot on Marshall's plaid shirt stemming from the apex of his legs and she blushed darker, if that was even possible.

"Fionna-"Marshall began. She didn't even hear the rest of his sentence as her mind adverted back to the last time she heard him say, actually scream, her name. That deep, husky moan. She wanted to hear it again but she didn't know why. Her panties still felt wet and it confused her. Did she have a cold? She certainly felt feverish. She shivered. "-doing in my house" he finished. She looked into his eyes right then and saw something there. Was it anger? Passion? Shame? …Love? No, it couldn't be, she assured herself. "I asked, 'what exactly were you doing in my house?' What did you see?" he repeated slowly, his last question nothing more than a whisper with a hint of fear. Fionna was starting to get defensive.

"I told you I was going to ask you if you wanted to go strawberry picking" she snapped and frowned. Deep down she knew his questioning was right. She should have left as soon as she saw that he wasn't in trouble. She had completely violated a very private moment. How was he ever going to forgive her? What if he found out she was there the whole time and hated her forever? Oh glob, what if she lost her best friend? What if they would never be the same again? She started to panic. Marshall opened his mouth to say something but she cut him off. "..but I got curious."

He stopped dead in his tracks, all coherent thought leaving his mind. They both stared at each other, daring the other to look away in the midst of this awkward confrontation. Fionna was first to tear her gaze away. "I couldn't help it," she admitted with a blush. "I'm an adventuress. I explore things that are new to me." Marshall smirked. He would never admit it, but she was turning him on. She was such a good little girl. Nothing prepared him for what she was about to say though.

"Can you show me?"

Marshall's face turned beet red and he sputtered as he stared at the innocent girl in front of him. "I-I uh...what? What do you mean…? You want me to show you my **junk**?" He combed a hand through his hair and looked toward the couch. Fionna blushed. "Well I've already seen part of it, I've never seen a naked boy before, and I'd feel more comfortable with you than Prince Gumball. I love learning new things!" She stopped talking and looked up at him suddenly with sad eyes "Actually never mind, I don't know what I'm asking, I really should leave." She looked away in shame and rejection.

"Don't go."

She barely registered what she heard before strong arms pulled her backwards and Marshall's lips crashed down on hers, his hands gripping her hips tightly, pulling her lower body flush against his. Fionna surrendered to the kiss, her lips moving slowly against his, letting him take the lead. She snaked her fingers into his raven hair, tugging gently. He groaned into her mouth, and she could feel his hardness pressed against her thigh, the material of her skirt riding up as he backed her against the door. They parted for air, and she felt Marshall's fangs graze the shell of her ear and she shuddered against his body, eyes closed, breathing laboriously into his shoulder.

**"I'll do more than show you, Fionna."**


	3. Chapter 3

**Author's note: Ya'll lucky I was in the mood to finish chapter 3 so quickly hehe~ I'm normally so lazy D; Sorry for all the cliffhangers! Gotta keep you coming back for something c: This is where the lemony smutty smut train goodness starts to pick up! Once again, feel free to review any errors you see, comments or suggestions! I check daily~**

**Still don't own Adventure time :'c waaah ;_;**

~0o0~

**"I'll do more than show you, Fionna."**

Fionna pushed Marshall playfully and he stumbled backwards laughing.

"Oh my glob Marshall you're so cheesy" Fionna giggled before tension once again filled the room. "So Fionna, what er...um…what exactly is it that you're curious about?" Fionna gulped. This was it. This was the point where she could either end it and go back to being best friends and pretend this day never happened, or push the boundaries of their friendship to satisfy her curiosity. She sighed lightly, feeling selfish. It wasn't fair for her to even consider using his body like this. It could mess up his feelings, and she most certainly did not like him that way! Or did she?

She closed her eyes for a second and thought of their friendship. She thought of how Marshall would always let his guard down around her and show her his playful side. How they could sit in comfortable silence and feel completely at peace and how she never feared him despite him being the dangerous Vampire King. He could kill her at any second if he really wanted to. She thought of his silky black hair, always messy as if he was too busy or important to run a brush through it. She thought of his pale, blue-tinted skin and his lean yet toned body. She thought of his lips, and how his skilled tongue would occasionally dart out and lick them when he was feeling playful or deep in thought. And she thought of him sprawled out in his bed, head thrown back in ecstasy once again, only this time, it was her small, delicate hand wrapped around his warm pulsating cock, pushing him over the edge with her tentative squeezes and experimental licks.

Her eyes shot open and she replied simply, "You." She seemed like she was in a daze so Marshall waited for her to clarify. "I just want to uh…explore you a little bit." Fionna blushed at her own forwardness.

He groaned softly. Her innocence was going to be the death of him.

"Well, I'm all yours Fi. Just don't jack me up or anything." He smirked floating over to sit with a plop on the couch, trying to lighten the mood. Marshall would never admit how many times he'd imagined Fionna taking control and having her way with him, nor would he admit how many times he'd find his own release from these erotic fantasies though. This was for her.

She sat down to the right him and suddenly it hit her. She had absolutely no idea what she was planning to do. Marshall watched her intently and chuckled. "You can touch me you know, I won't bite. _Yet_." He muttered jokingly. How much of that was really a joke? Fionna didn't want to know. She raised her right hand slowly turning slightly to face him and brought it down to rest in his hair. Marshall looked at her for a second, shock in his eyes. He did not expect this to feel so _intimate_. She was completely oblivious of course, raking her fingers through his messy hair and muttering about how soft it really was, twirling pieces of it between her fingers and giggling. Then her eyes rested back down to the moist patch on Marshall's shirt from his earlier escapade. "Can I take this off?" Fionna asked him softly, fear of rejection in her voice. Marshall chuckled and brought his arms above his head leaning casually on the couch.

"I told you, I'm all yours," he winked. Fionna smiled nervously and unbuttoned the shirt quickly, fearing he would change his mind. His sculpted chest and abs came in to view slowly, and Fionna's heartbeat quickened at the sight. When the shirt was completely unbuttoned, Marshall shrugged out of it and tossed it to the floor like a useless rag and resumed his nonchalant position on the couch, his eyes appearing closed, yet secretly glancing at her, peeking out through one eye. Fionna's hand came to rest on Marshall's abs, trailing a finger over the bumps and creases, feeling the light twitches of his muscles coming alive against her fiery touch. His breathing was becoming shakier, she noticed, and it was taking a toll on her body as well. Feeling more moistness pool into her panties, she pulled her hand back and fidgeted in place. Was she getting too intimate with Marshall? Should she stop?

That's when she noticed it. There, pressed against the zipper of his jeans, was the outline of his erection pointing towards her. His jeans were so tight she could practically see the exact size and shape in all its glory. Suddenly Fionna, the greatest hero of Aaa, was nervous and afraid. "What have I gotten myself into?" she thought. Her hand twitched but didn't make a move to explore this uncharted territory.

"Hey Fi," Marshall whispered, pulling her from her thoughts, "I can tell what you're thinking, and what you want to do. So I'll spare you the embarrassment and tell you right now, I want it too." She gulped and he smirked at her through half lidded eyes.

_"Touch me." _

When she didn't move, Marshall leaned forward and pecked her on the cheek before grabbing her hand and placing it over the tent in his pants. Fionna was stunned; her entire body seemed to have frozen up. "Fi? Did you die?" Marshall joked, poking her shoulder. She glanced down at her hand on his crotch, and gave it a tentative squeeze. The smirk left Marshall's face and his head fell back against the couch. "Ahh.."

Fionna squeaked "Oh my GLOB DID I HURT YOU MARSHALL?" releasing her grip on his penis. Marshall growled, his eyes flashing red for a second and grabbed her hand pulling it roughly back to his groin and squeezing her hand in his. "Don't stop Fi," he moaned, and she continued to squeeze at his erection, watching his chest rise and fall and his lips part. Marshall was squirming and groaning; his eyes were glued shut, his sighs and pants quickening as she squeezed harder. He seemed like he was enjoying it, but this wasn't enough for Fionna and rubbing his jeans was starting to burn the palm of her hand. Abruptly Fionna stopped and pulled her hand back slightly, staring at the zipper.

Without warning, she shakily tugged the zipper down and unbuttoned his jeans. "Here goes nothing," she muttered.


	4. Chapter 4

**Author's note: I'M SO SORRY THIS TOOK ME SO LONG TO PUBLISH ;~; I've been busy doing stupid little things like bleaching my hair to death and finishing mountains of homework I've been procrastinating on. Sigh, college life. To my readers/followers, thank you for all the lovely reviews! I check them daily and most of my decision to continue this was based on the amount of positive feedback. I was originally going to split this up into two chapters, but I decided nah, I'll just see how long this one gets and take it from there.**

**Would you like a lemon with that? Extreme smuttyness on this ship. Arrrgh matey.**

**Still don't own Adventure Time :'c**

~0o0~

"Here goes nothing," she muttered.

Pushing his boxers and jeans out of the way, Fionna stared down Marshall's erection, fully unclothed before her. She studied it, taking in every little detail of the organ. It was…cute, she decided, cheeks blushing a bright red at the thought. It was a blue-ish hue, just like the rest of him, only the head was a bit of a darker shade. The shaft was covered in a few veins, scattered evenly along the length; Fionna could see them throbbing, fueled by his excitement and anticipation of her touch. Her eyes traveling lower, she noticed the shaft tapered off into a small pillow-like shape with two small hairless lumps.

She giggled, "This reminds me of LSP" and poked the small sack. Marshall immediately sucked in a breath and bit his bottom lip, "Mmm...Fi.." "Woah, this is different," thought Fionna. The sack was soft, as though it was made of the finest velvet in all of Aaa, encasing two delicate balls. She brought her left hand down to cup his testicles gently, weighing them in her palm and petting them gently with her right hand as if they were precious. In a way, as silly as it may sound, in Fionna's mind, they were more precious than the greatest treasures imaginable because they were Marshall's. And Marshall himself was a treasure. Fionna couldn't bear to imagine any other female having her way with him like this. A surge of jealousy flashed through her mind over the thought. He was hers. But he was just a friend. How could she have envious feelings for a friend? She must be sick.

Once again his voice brought her out of her deep and untimely thoughts. "I really like that, Fi, it feels…nice…" She looked up to see him smirking at her before his eyes closed and his head fell back against the couch again with a husky sigh. Suddenly the past didn't matter, because he was with her now. Fionna let go of Marshall's balls and inched her fingers toward the shaft of his erection. Carefully, making a ring with her thumb and forefinger, she wrapped her fingers around the center of his penis and slid them slowly up and down. She could feel the skin sliding across the hard shaft, comparable to linen slipping against a wooden log. The warmth of her hand against the cool flesh of his cock caused Marshall to shudder, and he instinctively pulled Fionna's shoulder to his chest, her head resting comfortably in the crook of his neck as if they were watching a movie together. But this was no movie; Fionna's eyes were trained on his thick, warm manhood.

Fionna leaned against Marshall Lee, drinking in every slight movement of his body as she pleasured him innocently. Growing bold, Fionna grabbed the shaft of his cock with her whole hand and pumped a little faster, adrenaline filling her veins at his breathy moans. He was biting his lip, writhing beneath her and hissing slightly, "Aaahhh…Fionna…glob you're so good at this…fuck me don't stop please!" She blushed for the thousandth time at his obscenities. A small bead of liquid was beginning to form at the head of his cock and Fionna grazed her palm over it, dragging the liquid slickly across the underside of his erection. "MMMmm AHH!" Fionna stiffened in shock pulling out of his grasp as Marshall twitched, biting hard on his lip and turning his face toward Fionna's, burying it in the crook of her neck. Did she hurt him? His lips parted and she could feel his breath on her neck coming out in short pants; she could almost feel his lips curling into a relaxed smile against her skin. Nope. The butterflies in her groin were stirring again, and she rubbed her thighs together in a futile attempt to ease the throbbing ache.

Without warning, Marshall hissed into Fionna's ear with passion "I'm going to show you what you do to me, Fionna. This is how you make me feel. Faster now, don't stop no matter what," before gripping her face with both hands and crushing his lips forcefully against hers, his breathing jagged and hoarse. Fionna whimpered into the kiss and tugged as fast as she could; she grazed the tip of his cock with her fingers occasionally, collecting the beaded moistness and using it to lubricate the soft, sensitive head of his erection. Succumbing to Marshall's lust driven enthusiasm, Fionna groaned innocently into his mouth, parting her lips against his. Marshall took this as a chance to let his tongue slip into her mouth, exploring gently until he felt Fionna's small, delicate tongue tentatively touch his back. Fionna's left hand reached behind Marshall's head to fist at his messy hair matted with sweat, and she moaned into the kiss pushing him over the edge. Marshall screamed his pleasure into her mouth with a low groan, Fionna's eyes widening as she pulled away, watching streams of warm, white liquid shoot from the engorged flesh of his cock onto his abs. She looked back up at Marshall. His head was thrown back now, eyes closed, chest arching off the couch with his hands gripping tightly to the cushions, mouth in a silent scream.

Fionna stared at him wide-eyed and confused. She felt closer to him on an entirely different level, and didn't understand why. Sure, she had just witnessed her best friend get off by her own hand, and it made her proud. But honestly, it couldn't have been much different than if they had just been exploring a dungeon or cave together. Just two people learning something new from each other. Except it was nothing like that. Marshall trusted her with his body, enough to let her inexperienced fingers explore his length without even expressing the fear that she could easily injure the sensitive organ with one careless movement. It was private and intimate and too intense. Suddenly she was terrified again. These feelings were too much to handle in combination with the dull ache between her legs. She needed to get away and think.

"Fionna…" Marshall's body relaxed and he opened his eyes, focusing them on her, smirking at her, baring his soul to her.

"Your turn."He reached out to her.

"Actually Marshall it's getting late I'm gonna head out now" Fionna said in a panic, squirming out of his grasp and rushing to the door before she could succumb to his advances once again, blushing behind her bangs. Turning the doorknob quickly, she took a shaky step outside before bolting as fast as she could back to her tree house leaving a shocked, disheveled and confused Marshall Lee alone on the couch.

The last thing she heard was his voice filled with raw rejection.

**"What the junk, Fionna?"**


	5. Chapter 5

**Author's note: Meh~ I'm slow at updating. I swear it's worth the wait though! I've been swamped with so much work recently it absolutely sucks! Anyway, I was really conflicted in where I was going to take this chapter (and this whole story actually) from here. Thanks to my boyfriend (SHOUTOUT TO MY HOMEY BEEF) for feeding me some smutty idea fodder. I know where all this is going to lead now ;D Hope y'all enjoy this chapter, next chapter will be up in an hour or two. I PROMISE! Review Review Review! I feed off your lovely words. -makes creepy sucky noises-. **

**Still don't own Adventure time :'C**

~0o0~

**"What the junk, Fionna?"**

The door slammed behind her and she was gone. Marshall slowly stood up and stared down at the mess Fionna had left behind. That wasn't the only thing she left behind though. Marshall closed his eyes and let out a deep sigh. He could still smell her fresh, flowery scent and feel the tingling on his lips where hers had pressed tightly to his not long ago. He almost had her. He almost had the girl he loved. He gasped. "Loved? I don't love her. She's just a friend; one of the few people in Aaa that I can trust with anything," he thought to himself. And then it hit him. "What if we never see each other again because of this? What if we will never be the same?" With that, Marshall flew to his room, wiped the memories of their actions off his stomach, and tugged on a clean shirt and a gray hoodie before floating out the door. He had to talk to her. He had to make this right.

~0o0~

Fionna tuckered out halfway through the forest. She couldn't really run and think at the same time anyway, and she was definitely not ready to face Cake when she finally gets back to the tree house. It seemed as though even a simple "Hi baby how was your day?" would turn her into an emotional wreck. It was evening now, so all of Aaa was basked in the cool chill of the night air, and the sky was tinged in an array of pinks, oranges and dark blues. It was a beautiful evening to a perfect day.

Most of the residents of Aaa wouldn't dare enter the forest at this time of day, but Fionna had never been afraid. She knew nothing would harm her with Marshall around. Oh. _Marshall_. Fionna sighed and backed herself up against a tree, sliding down until she sat upright against it on the cool ground. She placed her face in her arms and closed her eyes. She needed some time to think. "I feel so pervy," she exclaimed exasperatedly out loud, "I can't even **look** at him anymore! I've seen his…j-j-**junk.**" Her face paled. "And I think I liked it...oh glob..."

Fionna tugged off her bunny hat to run a hand through her hair. Taking deep, shaky breaths she stood up and tucked the hat away in her backpack. She wanted to feel free tonight; after all, why not end the night differently? She certainly had spent her day differently. Shuffling her feet, she prepared for a not-so-peaceful walk home. There was a rustling in the bushes behind her.

"W-who's there?"

A hiss and a cackle.

"Who's there I asked? FACE ME, COWARD!"

She brandished her sword and pointed it at the offensive bush. "Relax Fionna it's just me, your _bad little boy_." Marshall floated out of the darkness with a smirk and a wink. Fionna blushed and looked away. "Why is he following me? What did he hear?" she thought. He looked gorgeous as ever, casually standing in front of her in that hoodie. His hair was still a mess from their earlier _adventuring_. The memories flashed through her mind and the ache was back. "Oh glob why now?" she thought. Her lips tingled and she suppressed the urge to run up and kiss him.

"I don't know what you're talking about," she muttered.

Marshall's brow furrowed and he looked down, kicking some pebbles. "Yo Fi, what's up with you? Why can't you talk to me anymore? I thought we were friends? Or is it because you realized you want to go try that junk out with Gumwad now instead." His last line was dripping with bitterness and hatred, his eyes fixed on Fionna's face, studying her reaction. Was there also a hint of jealousy? It couldn't have been.

"I don't know what you're talking about Marshall," she finally faced him "Prince _Gumball _is just a friend."

"Oh? So then what am I?"

"You're my friend too. You're my only other best friend, besides Cake, actually." she mumbled softly.

Before Fionna could register what happened next, she was pushed up against the tree again, Marshall's body pinning her there. He lowered his lips to her ear.

"So best friends sneak into each other's caves and watch them jack off? Then they tell each other they want to learn something _new, _give them the best orgasm of their entire existence, then leave and toy with their emotions? I don't think so Fi." He punctuated each question with his hand slowly sliding higher and higher up her thigh until it reached the hem of her skirt. She could feel his hot, moist breath against the side of her face as her fingers clung to the tree bark behind her.

His fingers grazed the edge of her panties, so close to her aching core."Don't lie to me Fionna. I could smell your panties getting wet back there. I can smell them right now. I'm a vampire, remember? I could teach you what that means. How to make that throbbing ache go away with your own fingers. Maybe even with _mine_. Don't tell me there isn't more to this than what meets the eye." Marshall grabbed Fionna's hand and placed it on the crotch of his jeans. "Feel that Fionna?" she instinctively squeezed the growing bulge and he hissed. "That's for you. Only you. You're the only person who's seen me this vulnerable." Marshall backed off then, thrusting his hands into his pockets and floated a couple feet in front of Fionna, giving her some space.

With eyes cast downward, he delivered his final words. "I may be from the Night-o-sphere, but I know my limits. I really like being your best friend Fionna, and I don't want to jack up this friendship any more than it already is. When the sun rises tomorrow morning, we'll go back to being the way we used to be before all this junk happened. I promise I'll pretend today was just a passing dream. Goodnight Fi."

Suddenly Marshall was gone, along with a portion of Fionna's heart. Her stomach dropped and she ran the rest of the way back to her tree house, tears slowly cascading down her cheeks.


	6. Chapter 6

**Author's note: Special delivery! Chapter 6, just like I promised! Enjoy! **

**SHOUTOUT TO SPECIAL REVIEWER Aircharmer5 WHO MANAGED TO TELL ME EXACTLY WHAT I HAD ALREADY PLANNED TO WRITE! Cookies for you! -tosses cookies everywhere- Child you have read my filthy filthy mind perfectly.**

**Meh I know it's getting boring but trust me it's building up to something good I promise! Same old, same old, review review review if you want more! Don't hesitate to throw suggestions at me, I don't bite! muahaha.. ^,..,^**

**STILL DON'T OWN ADVENTURE TIME ;~;**

~0o0~

Fionna barged into the tree house looking and feeling like a mess of emotions. She still wasn't ready to face Cake, nor was she ready to be left alone with her thoughts. She figured being alone was better than dying of embarrassment with Cake, though. Cake was in the kitchen boiling tea.

"Hey baby sis I-"

"I'm sorry Cake I need to be alone right now," Fionna cut her off and trudge into her room, slamming the door behind her. Cake knew better than to disturb Fionna after a long day of adventuring, so she sipped her tea alone and watched a movie on the couch with BMO.

Fionna sighed and slipped out of her adventuring clothes and searched around the room for her pajamas. Finding them discarded on the ground, she dragged herself to the bathroom to take a much needed shower. As she undressed and stepped under the heated sprinkling of water, Fionna rested her head back against the tiled wall and allowed herself to relax and think. To REALLY think. On the bright side of things, she had learned something knew today, and it was true that she would have much rather experienced it with Marshall than Gumball. She knew Gumball would be too shy and prissy about it all; what a baby. Ugh. What about Marshall though? He had feelings for her, that was for sure, but how deep did they run? How deep did her own feelings run? She didn't even know.

She had to admit, Marshall's body was sexy, and the thought of him disheveled and moaning her name surprisingly brought a sliver of warmth to her heart. Despite all the recent heartache, she knew there was absolutely no way Marshall could possibly want her as a girlfriend anyway, and so she decided it was best to leave their relationship as platonic. Exploring his body was one thing, but exploring his emotions would be too much for him. So why did that thought completely crush her heart every time it lingered in her mind? What if he found some other girl to toy around with? Fionna clenched her fists and frowned. No. He was hers, she would make sure of it, even if they could only be friends. Quickly she finished up with her shower, dried herself off and pulled on her fluffy blue pajamas.

~0o0~

Marshall Lee was a vampire, and vampires don't sleep. From his hiding spot behind a rock, he stared longingly at the tree house before him. As much as he wanted to barge inside the house and throw his heart on the line for Fionna, hoping she would want him as much as he wanted her, he had made a promise to her. Everything that happened to them from this point on would be all on her. After all, she had initiated everything from the get-go. He was just a toy for her to explore her sexuality, and strangely enough, he didn't mind at first. Now, however, something wasn't right. His heart dropped at the sight of her, and the breaths he didn't even need would become labored from the thoughts of her hand squeezing his rock hard cock again. Allowing his mind to wander to her head bobbing quickly between his legs, fingers gripping the bottom of his shaft as her tongue experimentally sucked the head of his erection aroused him more than it should have. To make it all worse, he now had real memories to fuel his imagination. This couldn't have been healthy. With a quivering sigh, he floated leisurely to her open bedroom window to watch her sleep peacefully, allowing himself to breathe in her scent and let his heart clench for her openly for the last time.

~0o0~

Fionna was a human, and humans needed sleep. Sleep was not coming easily for the adventuress tonight though. From her perch on the bed, she tossed and turned, unable to push her not-so-innocent thoughts of Marshall out of her mind. Her skin felt hot under her pajamas, and her body was involuntarily responding to the mental image of his erection, which she had become well acquainted with in only a day. Her mind reeled over what he had said to her tonight in a fleeting moment of passion before he disappeared. "I could teach you what that means. How to make that throbbing ache go away with your own fingers. Maybe even with _mine_." Did that mean she could make the ache disappear the same way Marshall had? But she didn't have a…thingy like he does. Oh glob there was that strange wetness again. Mustering up all her courage, Fionna slipped her hand under the waistband of her pajamas and let a finger slide over her wet panties.

"Ah!" she gasped, her other hand flying to cover her mouth before Cake heard. Glob forbid she walk in on this scene. Closing her eyes, her back arching slightly off the bed, Fionna slipped two fingers under her panties and dipped them into the moistness. It felt like an electric shock zipped through her entire body, and she wanted more. Fingers traveling lower, she encountered a small, tight hole. Terrified of what that hole was, she slipped her hand back up, palm sliding over the sensitive hood of her clitoris for the first time.

Extreme pleasure wracked her body, and she shuddered in the bed, Marshall's name slipping unintentionally from her lips. Was this what he felt when he thought of her? Is this what she did to him today with her hand? Spreading her own wetness across the sensitive nub once again, she stretched her legs farther apart allowing herself more access, blankets falling to the ground, leaving her exposed on the bed, pajama bottoms sliding down her thighs."Mmm..uhh…." she moaned into her hand. She was imagining Marshall in his red plaid shirt, ripped jeans open revealing himself again, but this time, sliding his erect member along the path her fingers were currently tracing. She wanted to feel Marshall's weight against her entire body, chest pushed roughly against hers, lips tracing her ears, collarbone and neck before finally colliding with hers. She wanted his hands in her hair, and hers tugging at his. Her fingers slipping frantically against her warm, wet lower lips, Fionna strived for some sort of release, not quite sure what it really was. With one final rub, she pushed herself over the edge; her eyes squeezed shut with a hoarse groan, "MARSHALLL!"

With a relaxed smile, Fionna opened her eyes. She wasn't quite sure what just happened, but it was definitely new and exciting. Biting her lip she thought of his words again. "How would it feel if Marshall touched me there instead..." she thought out loud.

There was a soft growl from her open window. With a surprised gasp, Fionna jumped out of bed and peeked outside. Nobody was there. "Now I'm hearing things. I must really be sick," she whispered before curling back up in bed and falling into a peaceful sleep.

~0o0~

Marshall's back was pressed against the side of the tree house directly under Fionna's window, out of her line of sight. The bulge in his jeans was painfully hard, and he rubbed it roughly trying to alleviate the pressure just a bit. "She said my name," he whispered, a smile grazing his lips. "Does she feel the same way about me? Does she even like me like that? Oh glob she's never going to forgive me for watching her like this. I guess we're even now…" He ran his hand through his messy raven hair and pulled his hood up over his head, gradually flying back to his cave. Maybe this changes things. All he could do was wait.


	7. Chapter 7

**Author's note: Waaaah I was suffering from intense writer's block all weekend! EXTREME SMUTTYNESS NEXT CHAPTER I PROMISE YOU FOR SURE. THE WAIT WILL COME TO AN END BY TOMORROW AND WILL CONTINUE ON FROM THEN. Shoutout to my homegurl torpeisnormal for being my most interactive reader so far! ~3 -tosses confetti-**

**Still don't own Adventure Time. Or Marshall Lee. -single tear falls-**

~0o0~

It was a beautiful day in Aaa; the sun was shrouded in clouds, no birds were letting out their nasty squacks, and not a single beast dared to roam the forests near Marshall's cave. It was perfect, almost too perfect. Marshall Lee was lounging casually on his couch, strumming the chords of his axe bass and humming a tune. Grabbing an apple from a table by the couch, Marshall sank his fangs into the delicate skin and sucked the color clean out of the fruit before tossing it into the nearest trash bin. Just like he promised, he was trying desperately to forget yesterday and pretend it was nothing but a beautiful wet dream. Floating leisurely to the kitchen, Marshall opened the cooler and noticed he was fresh out of strawberries, having stayed indoors all week. With a grunt, he slammed the fridge door shut and made his way to the bedroom. Almost as if the hidden sun had permitted it just for him, Marshall tugged on his gray hoodie and floated outside before heading off to the strawberry fields. Maybe picking strawberries would take his mind off of Fionna for a bit.

~0o0~

Fionna awoke to not a single ray of sunlight streaming through her window. For a second she thought it was still too early in the morning to get out of bed, but the scent of bacon pancakes told her otherwise. Sitting upright, Fionna let out a yawn and stretched. She felt very relaxed, surprisingly, after the emotionally exhausting day she recently had. Tugging on her adventuring attire, a blue skirt and a blue hoodie to accommodate the weather, Fionna trudged downstairs.

"Morning baby, have some pancakes," chirped Cake before plopping a pile of the meat cakes in front of Fionna. When she took a couple of bites of the pancakes, Cake continued, "I was gonna tell you yesterday girl but you seemed so out of it. Monochromicorn and I ran into Prince Gumball on the way to our picnic and he wanted me to tell you, he needs about 4 baskets full of fresh strawberries so he can start baking some tarts for the annual Candy Kingdom Bake Sale. He would do it on his own but he's just so darn busy with one of his crazy experiments again, that poor man. He needs them by tomorrow."

Fionna swallowed and rolled her eyes. "Sounds like another action packed adventure. I'll pick them today; I really need some time to relax." Finishing off her plate, she hopped up and made her way to the door.

"Uh, Cake..?"

"Yeah, baby girl?"

"Is it alright if I go alone? I want to get some fresh air. Besides, I know how you hate that dark forest."

"Sis you know that place gives me the creepies. You sure you'll be alright, Fionna?"

"Yeah I'll be fine, I promise." With a forced smile Fionna left the tree house to make her way through that forest once more.

~0o0~

Marshall Lee was hunched over a patch of strawberries, carelessly sucking the red out of one and tossing it behind him before plucking a couple more off the plant. A rustling of leaves behind him made him jump with a low hiss. He scanned the source of the noise from his spot on the ground. Oh. It was only Fionna. She didn't seem to notice him, as she got busy plucking strawberries out of the ground immediately. It seemed like she had a lot on her mind.

"Oh shoot." He heard her mutter. "I forgot to bring baskets to put these into." Lifting the hem of her hoodie like a small hammock, she began to drop strawberries into her makeshift basket.

Marshall chuckled. Since he had promised to be his playful old self again, maybe he could have a little fun with her like they had before yesterday happened. Sinking down on to the ground so that he was almost completely covered by the shrubs around him, he plucked a strawberry out of the ground and hurled it at Fionna. "WHA-" Fionna exclaimed as it hit her in the cheek, a bit of juice splattering across it. Before she could react, strawberries were flying at her in pairs, knocking her to the ground. "WHAT THE FLIP?" she yelled before popping up off the ground and running toward the source of the airborne fruit. With a mighty leap, Fionna straddled the perpetrator and was prepared to deliver a blow to his face before she realized who it was. Marshall laughed hysterically and Fionna's eyes turned to slits.

"What was that all about? Did you catch poo brain? Those hit me in the FACE. I'll kick your buns Marshall!" She began punching him in the chest.

"Hey don't go psycho on me Fi, you know my aim is pretty radical!" He smirked before flipping them over so that he was on top. Quickly he leaned down before pecking her on the cheek where the strawberry had hit her, his tongue sliding sensually across her skin. "What the lump…" Fionna blushed when he pulled away. Marshall grinned toothily showing off his fangs. "Red. Strawberry juice is red, butt-brain." Fionna blushed even more. She should have known he was just being friendly. What did she expect? Things were just about normal again. She pushed him away and stood up, dusting herself off.

"Hey Marshie do you have any extra baskets? I need to borrow like 4. Prince Gumball needs these berries for the bake sale." Marshall scoffed, inwardly beaming at her nickname for him. "Why would I wanna help Gumwad? He's such a lumpin' lady." Fionna pouted, lower lip jutting out like a kicked puppy. "Please Marshie? Or I'll call you Marshmallow Marshie for the rest of your life! You're nothing but a little softy anyway" she giggled. "Dear glob did you just come up with that now? Please stop before you ruin my reputation" he rolled his eyes sarcastically. "Besides, I told you, _I'm bad but not little,_" he muttered, his voice dark. Fionna shivered. She was well aware of the part of him that wasn't _little_. "Whatever, I have some extra baskets in my cave, wanna head over there?" With a nod and a grin, Fionna followed Marshall home.

~0o0~

The walk through the forest was an uncomfortable silence. The playful joking had died down immensely, and all that was left was a thick air of mixed emotions.

"Heh..so Fi, how's Cake doing?"

"She's fine, just been busy with Monochromicorn. You know the business."

"Heh..heh..gettin' busy." Fionna smacked Marshall in the arm.

"You're so pervy." More awkward silence.

Fionna's mind was reeling. "Why isn't he talking? Is he thinking about yesterday? Why won't he talk about it with me? I kind of want to…"She was jolted out of her reverie when they finally arrived at Marshall's cave. "Ladies first," he smirked and she stepped inside.

There was the couch. Memories flooded back and they both just stood in the room staring at it, a thick air of yearning filling the space around them. Feeling suffocated by his urge to take things to the next level, Marshall floated away and busied himself searching for the baskets. Finally alone, Fionna approached it slowly and sat down bringing her knees up to her chest. She stared at the TV set.

"Hey Marshall, can we watch a movie right now instead? Technically I don't need to have those strawberries until tomorrow. We could go again later tonight. That way it would be more like an adventure in the dark and all."

"Uh, sure I guess. Why don't you pick one out of that shelf over there? I'll be out in a sec." Fionna hopped off the couch and approached the shelf. "Hmmm… what to watch…" she muttered. She scanned the shelf to find an array of classic horror and zombie films. One film was shoved haphazardly into the shelf on its side. Plucking it out to fix it, Fionna's eyes widened in shock. On the cover in bright red were the words "Sexy Vampire Suck-Off XXX" and a couple scantily clad pale females stood in awkward poses revealing their lumps.

"Whatcha got there?"

Fionna nearly jumped clean out of her skin. Marshall peeked over her shoulder and paled, sputtering slightly. "Oh glob Fi, sorry you had to see that," he blushed, grabbing the movie and shoving it back on the shelf.

"How about we watch this zomb-"

"No."

"What?"

"No. I want to watch that movie you just put back."

"W-what Fi, are you crazy? That movie's too globbin' _nasty_ for you. Your eyes will bleed and then-"

"No."

She pulled it out of the shelf and shoved it in his arms. "I wanna know what this is. It's about vampires right? Is it gory? I'm used to action, why would it be too much for me? I'm an **adventuress**. I want to know what it's about. Nothing's too scary for me. Or is it because you're the one scared? You're such a wuss, Marshall!"

Marshall huffed. "Fionna this is a, uhm…a _different_ kind of movie." Fionna squinted at him. "How?" "Well, uh, they're gonna get naked and junk." Her nose scrunched up. "That's it?" He sighed, "No. Then they touch each other, you know, kinda like what happened yesterday…" he trailed off, mentally kicking himself for not keeping his promise. Fionna perked up and grinned, "I still want to watch it! It's like learning something new!" She would never admit she just secretly wanted to watch something erotic with her best friend. She shoved him over to the TV and plopped herself down on the couch behind him. Marshall awkwardly pushed the disk into the TV and ran a hand through his hair before settling down uncomfortably next to Fionna on the couch. Glob help him. They were about to watch _porn_ together on the very couch Fionna had jacked him off on just the day before. He cast a nervous glance toward her but she was too enthralled by the upbeat music signaling the introduction of the film to even notice him.

A pale female appeared on the screen wearing nothing but a g-string thong and a tight, cropped black t-shirt. Was she supposed to be a vampire? She seemed rather human. How old was this film and where did Marshall get it? The female sauntered over to a male who was sitting casually on a bed. He was saying something to the female, but Fionna wasn't paying attention. She was studying the girl in the film. She was slender with large, round, perky breasts and beautiful curves. Fionna cast a glance downward at her own body and frowned. She was curvy, but certainly not as slender as the girl in the movie. Nor did she have perfectly tamed hair, an exceptionally girly wardrobe, or a face caked with makeup. Was that the kind of girl Marshall liked? No wonder he wanted to go back to being just friends. Fionna's demeanor drooped slightly, but she didn't want Marshall to notice and stop the film. She wanted to learn more. She glanced at Marshall in her peripheral vision and saw that he was blushing furiously, eyes trained on the wall and not the TV.

Somewhere in the midst of her thoughts, the couple in the film had stripped each other bare, the man lying back on the bed while the woman slid her hands across the planes of his body. Her hand grasped at his erection and stroked rapidly. Fionna gasped. "MARSHALL LOOK! I did that to you!" Marshall jumped, tearing his eyes away from the wall and glancing at the TV. "Uh..yeah.." he turned away again. Oh glob the tingling was traveling through Fionna's body again, settling in her groin. The film continued, and the female had managed to crawl between the man's legs and was both licking and stroking his penis. Fionna studied the fluid movements. "That looks like fun..." she muttered, forgetting Marshall was right next to her. She felt him shift uncomfortably on the couch in a feeble attempt to hide his raging boner from her eyes. Fionna pretended not to notice. The female was now on her back with the male between her legs. Fionna sucked in a breath. This is what she wanted to learn. This is what she needed to see. Fionna scooted closer to Marshall on the couch involuntarily and rested her head on his shoulder as his body stiffened in shock. As weird as it may sound, she wanted to be as close to Marshall as possible. She watched intently at the scene, the man's skillful fingers prodded and slipped gently along the woman's slit before rubbing furiously. He leaned down, spreading slick moisture along her lips before his tongue darted out to graze the sensitive bud. In one fluid motion, his mouth enveloped her clitoris and sucked roughly, the female moaning in pleasure and gripping at his hair.

Fionna sat upright and screamed, "He really is a vampire! Oh my GLOB HE'S EATING HER MARSHALL."

"Figuratively…" he muttered.

"What?"

"He's not really eating her Fi. He's just, you know, _pleasuring _her."

"Doesn't that hurt? What about his teeth?"

"Uhm, well, I wouldn't know cuz I'm not a girl and junk." Marshall blushed and turned away. There was a gentle tap on his shoulder.

"Hey Marshie…" Fionna began, eyes trained on the carpet.

"Yeah?"

"I'm a girl and junk…"

Marshall stared at her confused.

"Can we uh, can we maybe try that? You know, since we already tried the first thing yesterday…"

Marshall blinked, considering it for a second before coming to his senses. "Glob Fi, you're gonna jack up your innocence by asking your friends questions like that. I don't think you're ready fo-"

Fionna felt tears of rejection forming in her eyes. Jumping off the couch, she stood directly in front of him. "FINE THEN I'LL JUST ASK GUMBALL TO TEACH ME INSTEAD."

With a snarl, Marshall grabbed Fionna's hips and dragged her onto his lap, pulling her core flush against the hard bulge in his crotch, hips bucking slightly at the contact. Fionna moaned at the new contact, head dropping to Marshall's shoulder blade.

"You asked for it this time. Don't you dare leave me hanging again, Fionna."


	8. Chapter 8

**Author's note: -blushes- dear god somebody take Adventure Time and my laptop away from me before I pour more lemonade on your helpless eyes. As promised, here's chapter 8! Remember to review! It's so early in the morning right now I'm too lazy to proofread this ;~; Happy reading!**

**Still don't own Adventure Time. -grunts- you know duh drill.**

~0o0~

"You asked for it this time. Don't you dare leave me hanging again, Fionna."

Fionna's senses were in overdrive. Despite her head being buried shyly in the crook of his neck, all she wanted to hear and feel was Marshall Lee. His hands gripped her hips tightly and she instinctively swiveled them against his groin. "AHhh" they moaned together at the new feeling. Fionna's breathing became shaky and her hands fisted in Marshall's hair. They were still wearing too many layers of clothes. Marshall gripped Fionna's hips tightly with one hand to stop her from making any sudden movements and used the other to lift her chin to look at him. His eyes bore into her soul.

"Fionna," he whispered, "do you trust me?" She huffed, eyes glazed over with lust "Yeah of course I do Marshie." She punctuated the statement with a poke to his forehead. He chuckled. "But I'm from the Night-o-sphere, remember? I'm _bad_. I could hurt you. I could take _advantage_ of you." Fionna scoffed. Marshall was trying too hard to scare her away. This was boring. She tried wriggling around on his lap to bring the spark back. Marshall hissed. "I told you I trust you, Marshall. You're my best friend, duh. Besides, if you were gonna take advantage of me you woulda done it by now," she beamed.

"You sure about that?" Marshall smirked before wrapping Fionna's legs around his waist and carrying her swiftly to his bedroom and tossing her on the bed.

"Scared yet?" he whispered, towering over her. Fionna giggled and his grin faltered. Fionna grabbed the collar of Marshall's hoodie and pulled him down. He let out a breath in shock. "I'm the greatest hero in all of Aaa. You don't scare me," her breath tickled his ear. They stared at each other on the bed in silence, Marshall lay over Fionna, arms barely propping himself up, eyes challenging, waiting for the other to make a move. Fionna reached a finger up and traced Marshall's lips and they parted slightly, his eyes closing at the intimate gesture, letting out a breath he didn't know he needed. She studied the way his fangs were barely visible yet still there, enticing her, daring her to delve in and slide her tongue over them; his mysteriousness fueled her craving for his touch.

"It's your turn, Marshall. _Touch me_." The invitation rang loud and clear in the quiet room. Marshall's eyes widened and he cocked an eyebrow but he didn't make a move. Fionna squirmed, feeling uncomfortable under his gaze. "Why should I?" Glob he was trying to be playful again? She would skin him alive if only his tone hadn't been so _hot_.

"Marshie _please_ I don't understand. I get this weird feeling when I'm with you and it's like there are thousands of butterflies getting funky in my stomach and then I think of yesterday and the butterflies fly lower and it's uncomfortable. It almost hurts. And then we watched that movie just now and the butterflies came back and that man looked like he was fixing them for that lady _please fix it_, you said you knew how…or did you lie to-"

Soft lips crashed down on Fionna's cutting her off mid sentence, his fangs grazing her lips before they parted in invitation of his tongue. Marshall was everywhere at once, one hand gripping at Fionna's bunny hat, tugging it off and tossing it to the ground so he could tangle his fingers into her luscious blonde hair, their lips still connected. Fionna could feel Marshall's jean-clad erection brushing her thigh and she reached a hand down to pet it. He let out a strangled moan and grabbed her hand, leaning down to whisper in her ear, "Today it's about you." His lips returned to their assault on hers, softly biting and nipping at her lower lip and sliding his tongue over the raw flesh.

Suddenly, Marshall's voice dropped to a husky undertone, his eyes glinting mischievously. "So tell me, Fi, is this what you want?" His other hand abruptly slipped under her skirt, rubbing tight circles over the moist and swollen lips. It was so sudden, and so _sexy_. "Oh GLOB Marshall YES!" Fionna screamed, spreading her legs wider on the bed in hopes of gaining more friction. Their kissing became more frantic, Fionna tugging at Marshall's hair and bucking her hips against his fingers, legs wrapping around his waist desperate for release.

Then he stopped.

"W-what?" Her legs dropped.

He sat up on the bed and smirked down at the disheveled, glassy-eyed heroine beneath him.

"M-m-Marshall? Why'd you stop? Did I do something wrong?" she pouted.

His smirk turned into a grin. He lifted his hands as if to smooth her clothes back into place and tell her to leave.

"Marshall wha-"

3 – 2 – 1.

The sound of clothes tearing filled the room.

"What the GLOB, MARSHALL?!"

In his right hand he held her panties, torn down the seam and utterly useless. Blushing furiously, Fionna tried to cross her legs feeling too exposed. The panties were haphazardly tossed on the ground and Marshall's hands gripped at her thighs holding them apart. "Stop Fi, you don't need to hide anything from me. We're best friends remember?" His smile melted her heart. "Just relax and trust me."

Marshall stared at Fionna's pussy glistening with her lust for him. His eyes dilated as he inhaled her sweet, flowery scent concentrated in her groin. He shivered inwardly at the thought of his thick shaft buried deep in her folds thrusting wildly, and the thought-provoked sensations settled in his crotch. He could feel beads of precum escaping his cock and dripping down the head through his jeans. She was so innocent, yet this felt so right.

He lifted a finger and slowly ran it down the slit, no layers of clothing blocking out the sensations. Fionna's head fell back on the bed, all coherent thoughts of shame and embarrassment leaving her mind for good. "Hhhhngg Marshall…" He spread the moisture all across her lower lips, occasionally brushing his knuckles over the sensitive bud. "AHHhh!" Fionna's body jolted, her back arching slightly off the bed, sweat beginning to glisten on her brow. "Please don't stop…" In her fit of pleasure, Fionna didn't notice Marshall's head leaning lower and lower until she felt something hot, wet, and warm caressing her most private regions. Her eyes shot open to see Marshall's face buried at the apex of her spread legs, raven hair tickling her inner thighs. His tongue was moving slowly, almost lazily across her over sensitized flesh, stopping to pay special attention to her clit.

"Mmm..AH..M-Marshall…this is so..hnng…embarrassing…please..uhhghh.." She couldn't find the words to stop him as his tongue snaked its way around her lips, sliding between the folds of her pussy, sending hot, electric sensations through her quivering body. "Marshie…" she breathed, "that feels so…mmm…good..." Fionna felt him grin against her lips, fangs grazing her bundle of nerves and she sucked in a breath. Something about his fangs was just so _erotic_. Maybe she would tell him that someday.

From his perch between her legs, Marshall looked up, eyes turning a deadly shade of red, staring straight into Fionna's. "Remember who's name you'll be screaming today, Fi. _Mine_. Don't ever forget that. _I'm_ your best friend. _I'm_ the one with my face buried between your legs, giving you the pleasure you deserve. I may be bad, but you make me feel _good_." His eyes softened almost in fear, "Remember me after today and forever, and don't go running to _him _when you realize I'm not lumpin' sugary sweet enough for you. **_Please_**." The last word was barely a whisper and Fionna didn't need to think twice to know what he meant.

Before she could respond, his lips fully enveloped her clit and sucked roughly. Fionna's hands gripped the bed sheets beneath her, arching her back clean off the bed and groaning heavily. She could feel his teeth grazing her flesh and his hands gripping her thighs and his hair scratching her legs and it was all _Marshall _and it's like the stars had aligned just for her. They were both panting heavily, Marshall's breathing was shaky while Fionna's had become erratic. With his lips still assaulting the little nub, Marshall gently wiggled a slender finger into her tight hole, feeling it slide easily through the moisture as her muscles clenched around it. Oh what he'd give to replace that finger with his throbbing cock, feeling her tight walls massage and milk him to completion.

Curving his finger upward, Fionna wriggled a bit at the intrusion, moaning and gasping softly as his tongue and finger sensually massaged her core. The sensations were too much, Marshall's breathing and soft coaxing setting Fionna's body on fire, and she let out a strangled cry, fingers latching tightly into Marshall's hair, pushing his face as close to her as possible and swiveling her hips so his tongue hit her in just the right spot, pulling her over the edge. "MMMMmmmm-MARSHALL! UhhHNNNGG!" she screamed, her head thrown back against the pillows beneath her. Fireworks exploded behind her tightly squeezed eyelids, and she bit down on her lip so hard it almost drew blood.

Fionna was too busy riding on the waves of pleasure to notice Marshall place a small kiss to her satiated folds, and another to her inner thigh before sitting upright and adjusting himself in his jeans to ease the discomfort. Fionna breathed heavily, crossing her legs over each other and reaching out absentmindedly for Marshall's body. Coming down from her high, she could finally sense the reality of where she was. She smelled Marshall on the pillows and sheets, and realized she had grown so accustomed to him that she may just go insane if she didn't bring one of his shirts home with her or something. Maybe she'd sneak one out later. He chuckled and lay down beside her on the bed, and she turned to face him. Both their cheeks were stained pink, Fionna's from the afterglow and Marshall's from the exertion. "Uhm…wow..." she muttered, biting her lip. Marshall smirked and pulled her into a hug.

"Thanks Marshie," she smiled into his chest.

"No, thank _you_, Fi, for trusting me."

"Aren't we supposed to get naked now?"

"Wait, what, now?! W-why?"

"I dunno, they were naked in the movie. What happens next?"

Marshall gulped. "Well, Fionna…"


	9. Chapter 9

**Author's note: WOOPS sorry it's been so long ;~; I'd explain it all to you but I know y'all could care less about my college workload LOL. Anywhooooo~ Here's the chapter you've been waiting for! It's the longest of them all, and I was considering splitting them up into two chapters but I couldn't for the life of me figure out where I could make a clean transition between the chapters. Of course, laziness won in the end so it's all mooshed up together. meh. Hope you enjoy it! I HAVEN'T PROOFREAD IT YET SINCE IT'S LIKE 4 AM RIGHT NOW AND I'M TOO TIRED SO IF YOU SEE A MISTAKE OR SOMETHING PLEASE PM ME SO I CAN FIX IT. and review review review if you want more! **

**OH OH OH AND ONE THING. I received some reviews as to why Fionna's really innocent to the point where I'd almost be embarrassed for her poor soul. Anyway, If you think of it logically, she lives in a treehouse with a shapeshifting cat as her only adult/parental figure, and everyone around her is either some crazy monster or some strange creature or a prince. None of those seem like people who would bother teaching her the details on copulation if you ask me. Whatever knowledge she has would have to be minimal and fueled by most likely a crude joke or something. Or maybe I'm just reading too much into the character. Either way, her innocence slips its way out the door in this chapter so y'all don't needa worry bout that anymore. WOULD ANYONE LIKE SOME LEMONADE FOR THEIR EYES? -pours jug of lemonade on everyone- yeah yeah you get the picture. HAPPY READING!**

**Still not owning Adventure Time how sad ;_;**

**~0o0~**

Marshall gulped. "Well Fionna…when a man and a woman like each oth-"

"NO NO NO. I don't need _the talk_ Marshall, I know enough! I'm not 10." Did he really think of her as just a kid? Fionna's nose wrinkled in disgust. "I mean what happens next _for us_." She blushed hard and Marshall fought the urge to kiss the delicious red clear off her face. Casually propping his arms behind his head, Marshall looked directly into Fionna's eyes. "Whatever you wanna do, Fi. We could take this to the next level if you're ready, or we can just, you know, pretend this never happened. It's going to be really hard for us to forget though, so don't say I didn't warn you. I'll wait for you anyway; I know you can't resist these lumps." He smirked at his own LSP joke. All joking aside, Marshall's tone dropped slightly and he muttered "But hey, just so you know, I'm not gonna lie, I really want to try this with you."

Fionna giggled nervously. She already knew what she wanted to do. She was ready to step it up and give Marshall her body, and she didn't even really know why. Maybe it was just because she was feeling exceptionally adventurous and Marshall had just delivered her a mind blowing orgasm. She felt her face heat up. Or maybe it was something more. Her heart clenched at the thought of forgetting everything they had done together in the past couple of days and moving on. Was she really going to push the boundaries any further? He was her best friend! Shouldn't she wait for Gumball or somebody she would marry? What if Marshall really would take advantage of her? Fionna's mind reeled with questions that didn't even need to be answered. What mattered was here and now, the present, and the only thing in her presence was Marshall Lee. Fionna was vulnerable, but she was also curious, and her excitement bubbled in her chest. She was done over thinking and ready to let her emotions guide her.

Fionna groaned and pressed her hands to her face. "Ireallythinkweshouldjustdoit Marshall," she grumbled quickly into her hand, too embarrassed to face him despite all they've already done. His eyes widened and he faced her on the bed, mouth agape.

"W-what was that, Fi?"

"We should do it. Take it to the next level, I mean." She turned away, blushing at the wall.

Marshall sputtered; he did not expect it to get this far. What if he messed her up and they spent the rest of their existences avoiding each other? Not to mention all the emotional ties that would come with it.

"You wanna _do the nasty_? With _**me**_? But why?"

Fionna punched him in the arm to avoid the subject. The last thing she wanted was for him to know she had feelings for him, or that the feelings had stemmed from their most recent "adventures".

"Stop asking questions Marshie. Do you want to try it or not?"

It was Marshall's turn to blush. What kind of question was that? How many days and nights had he spent alone in his room, hand gripping and massaging throbbing meat, daydreaming of the moment he would finally turn the good little hero into his own, personal, bad little girl. He wanted her all to himself, but he would never dream of pushing her to be his, nor would he have ever imagined that she'd voluntarily ask for him. Something had certainly changed between them. Marshall's deepest fear began to snake its way into his mind and heart. What if she would take him this one time and use her knowledge to seduce that Gumwad in the end? Would he have to watch her walk down the aisle from the back of a crowded room in the Candy Kingdom, knowing full well what they had done together, living the rest of his life thinking of what could have been? She had full control over him without even knowing it, and he didn't like that one bit. She could break his heart. Can vampires get broken hearts? Did he even have a heart? He didn't want to find out the hard way, that's for sure. But this was Fionna, and she was his weakness; she was like the color red. Sweet, deadly, unknowingly seductive, and he needed her to survive. Where would he be without her friendship? He didn't want to lose her, and he would give her whatever she wanted to keep her in his life, if only as a friend in the end. _Whatever she wanted. _

"I, uh, yeah sure, I mean of course…but, are you ready for that kinda thing, Fi? Don't you wanna wait for someone better? It's kind of a big deal and all." He closed his eyes, tears of rejection already beginning to prickle at the corners of his eyes, ready for her to come to her senses and run away to Prince Gumball.

Fionna beamed and tapped Marshall's nose with her finger. "There's nothing better than the best, and you're my best friend! Besides, we've gotten this far already."

There was a shifting and the sound of rustling cloth. Marshall opened his eyes to see Fionna was sitting up on the bed, legs crossed, skirt barely covering her bare core. Her blonde hair clung to her forehead and trailed down her back, pooling around her on the bed. Her deep, blue eyes held thousands of emotions as they sparkled, cheeks tinged with pink, as she hungrily eyed the vampire on the bed. Despite the melancholy that had wormed its way into his mood, Marshall felt himself growing hard all over again. He closed his eyes again and sucked in a breath, wondering how he would make the first move without frightening her away. He didn't have to think for long. "AAHhh!" Marshall moaned; his eyes flew open in surprise, hips jerking slightly off the bed. Fionna gripped his length through his jeans, palming roughly and giggling innocently at Marshall's reaction. "Aaahhh, uhh, Fi… mmmm, we should probably take off our….uhgghh, clothes…" he struggled to form a sentence under her ministrations. The fact that Fionna made the first move not only shocked Marshall, but turned him on immensely. She was the one girl he would allow to control him this way; he only wished she knew that though.

Carefully, Fionna reached for the button of Marshall's jeans and slowly inched it out of the fabric. As she unzipped the fly, Marshall instinctively spread his legs slightly against the sheets, and Fionna crawled between his legs, fingers teasingly brushing the bulge of his jean-clad erection. It was such a simple gesture, and yet Marshall felt his body reacting to her touch, his breathing becoming shallow as his tongue involuntarily ran along the tip of his fangs. In one smooth move, Fionna grabbed the waistband of Marshall's boxers and tugged them over his shaft, releasing his aching member. With the material bunched up under his balls, Marshall's jeans still constricted his movements, and Fionna had complete power of the situation.

"I kinda wanna try something, if that's okay…" Fionna whispered. She sounded nervous despite her forwardness.

"Whatever you want, Fi, I'm yours." Marshall winked, trying to sound playful. Nevertheless it seemed as though the more he said it, the more he meant it and believed it himself. There was a brief silence as they stared into each other's eyes, wondering what was really happening between them.

Fionna turned her attention back to the task at hand. Without warning, she leaned down and touched her delicate tongue to the tip of his tender cock. "Oh GLOB." he whimpered, biting his tongue at the warm sensations coursing through his body. Satisfied by his reaction, Fionna allowed her fingers to slide up, under Marshall's hoodie to caress the muscles there, as her tongue swirled over the throbbing flesh of his manhood. Marshall's head was thrown back, lips parted as he drowned in Fionna, feeling every slip of her tongue against his most sensitive regions. She trailed the wet muscle from the base of his cock to the tip, and, with a small squeak, enveloped the head of the organ in the moistness of her mouth. Marshall hissed, fangs bared as he bit his bottom lip hard, one arm haphazardly thrown over his face, the other reaching down to fist in Fionna's hair. She bobbed her head slowly, taking in the new experience with care. "It tastes different, but in a good way," she internally decided. There wasn't much room for coherent thought though, and she worked on instinct, fueled only by the rush of blood coursing through the pulsating veins and the husky moans of the king quivering beneath her. One of Fionna's hands gripped the sheets below them for balance; the other gently squeezed the base of Marshall's penis.

"Mmm..you don't…have to…ah..do…this Fionna…" came a choked whisper, and Fionna stilled, shocked by his concern for her in the midst of passion. Fionna sat up, hand replacing her lips to stroke his shaft slowly, a quizzical expression on her face.

"Why not?"

Marshall groaned, trying desperately to hold a conversation with her while she stimulated him. Did she even realize what she was doing to him at this very moment? "W-well, I, ah.. a lot of, girls uh, don't like to, mmm, use their mmm-mouths…cause they think it's gross and junk…uhhggh.." Fionna scoffed and stopped her ministrations.

"Then they're cowards! What's so gross about it? I for one think it tastes _good. _And I'm happy you trust me enough to give me a chance to try it on you. I trust you too…and besides, it's cute when you moan like that." She tucked a strand of hair behind her ear and turned away. Marshall just stared at her, unable to fathom the words she just said to him.

Something clicked in his mind and it's like everything made sense. Fionna was _here_ and she was his if only for this moment and nothing would ever tear them apart. This wasn't even about the experimenting and the touching and the learning anymore. He trusted her. Fuck, he _loved_ her. He wasn't going to hide it anymore, at least not to himself. He loved her hair, her beautiful blue eyes, and the way her lips curled into a smile at the thought of an adventure. He loved the way she brandished her sword with confidence and bravery and protected the land with her heart of gold. He loved her honesty and he loved her little bunny hat. He loved her blush, her lips wrapped around his cock and the way her fingers gripped his hair when they kissed. He loved her to Lumpy Space and back, and he wouldn't deny it to himself anymore. He needed her. But he couldn't let her know how he felt yet. He just couldn't. It would mess everything up.

Marshall sat up without a word and lifted his hoodie and shirt over his head in one swift motion. He kicked off his jeans and boxers and sat on the bed before Fionna completely naked, baring his body to her. Gripping Fionna's hips, he pulled her onto his lap, erection brushing her moist lips and they both threw their heads back and groaned at the intimate skin on skin contact for the first time. Marshall's hand slid up under Fionna's jacket encountering bare skin and he felt her tense up, eyes widening in fear.

Marshall lifted a finger and tilted Fionna's face so that she looked at him. "Just let go, Fi. Trust your body. Trust your heart." And in that moment, Fionna didn't just see Marshall Lee the Vampire King. She saw Marshall. Marshie. Her best friend, the boy who would annoy the biscuits out of her with his pranks, the boy who would laugh at his own jokes, and the boy who would sing her his songs while strumming his axe bass. She saw someone she could laugh with, fight with, go on adventures with, and spend her life with. She saw a friend and a lover and her heart almost burst with the raw emotion. But she couldn't let him know how she felt yet. She just couldn't. It would mess everything up.

So Fionna leaned down and kissed him, soft tongue trailing over his lips, and fangs when they parted, hips grinding roughly into his erection, their lower halves slipping against each other in an intimate dance; so close to what they both needed, yet so far. When Marshall's fingers slipped under Fionna's hoodie for the second time, she didn't even flinch. Instead she lifted her arms and gave him the room he needed to pull the articles of clothing away, leaving her in her skirt and simple, white bra. Marshall reached around to unclasp her bra, and it fell off the side of the bed and away. Fionna blushed but didn't hide herself. She trusted him with every ounce of her being, and she giggled at the tickling sensation when Marshall ran his fingers over her beautiful, full breasts for the first time.

"Yo Fi, for the record, I've always thought you were globbing perfect." He grinned at her, before pulling her into a hug and laying them both down, her body straddling his. With one last article of clothing in the way, Fionna wiggled her hips and squirmed out of her skirt, tossing it behind them.

There was a brief silence as they both took in their surroundings. The room had darkened significantly since they started, clouds shrouding out the sunset completely. The only sound that could be heard was their shallow panting as they gazed into each other's eyes. "You ready, Fionna? There's no turning back now." Fionna gulped and responded by swirling her hips over Marshall's cock, eliciting a low growl from him. "Alright Fionna, I'm going to teach you how to _feel_."

Fionna gasped as she was abruptly flipped over, hair cascading around her like a halo. Marshall floated above her slightly, trailing gentle kisses down her neck, pausing to nip at her pulse point, hands firmly planted on the sheets beside her. Fionna groaned. She knew he wanted her to beg for it. "Touch me, Marshall." He smirked against her neck, and his hands rested on her breasts, kneading them and massaging them tenderly. Trailing hot, wet kisses across her collar bone and down to her chest, Marshall tentatively licked at Fionna's right nipple, pulling it lightly into his mouth. The sensations were overwhelming, and Fionna reached up to pull Marshall's face closer to her chest, craving more of the heated contact. He grinned against her chest, pleased by his work as she bucked her hips, desperate for stimulation. Marshall pulled away for a second, only to provide the same attention to her left breast as well. "Please, Marshall…ahhh.." Fionna mumbled, closing her eyes and losing coherent thought at the feeling. Suddenly Marshall pulled away again, and she could feel him staring at her through the shadows. She looked up, and he indeed was staring at her intently.

"Are you _**sure**_, Fi. It's the last time I'm gonna ask."

She smiled and nodded, reaching between their bodies to stroke his slick, moistened cock, letting him know she was ready. Marshall floated a few inches above Fionna, head buried in the crook of her neck as he spread her legs, running a finger through her folds before slipping it inside her pussy. He rubbed her clit with his thumb while simultaneously thrusting his finger before slipping a second one in, trying to stretch her as much as he could to ease the incoming pain. Fionna bucked into his hand, fingers latching into his raven hair, feeling his teeth graze her shoulder. "AAaahh Marshall, more!" She moaned, and he took a deep breath. It was now or never. Lifting his face to kiss her, Marshall gripped his length and rubbed it against her clit before sliding it into her tight, virginal opening. Fionna squealed in pain, but Marshall swallowed the sharp agony with a slow, sensual kiss. "Shhh, Fi, shhh…it will feel better soon I promise." Her eyes were squeezed shut in pain, but she refused to scream and shame herself.

Marshall was still. If his 1000 years of existence were to end in this very moment, he would have been content. Sheathed and devoured by her warmth, Marshall could feel every squeeze and clench of her tight, warm, muscle walls, and he would give anything to feel it for the rest of his life. So caught up in his thoughts was Marshall that he didn't even notice Fionna squirming uncomfortably until the soft whisper and a thrust of Fionna's hips yanked him from his thoughts.

"You can move now, Marshie, it stopped hurting."

It was as though time suspended for the two of them alone. All the pent up need, passion, and lust between the two were released, and Marshall's lips devoured Fionna's hungrily. Slowly Marshall pulled out, only to thrust in again, the friction causing them both to scream into each other's mouths, setting their bodies on fire. Fionna's legs wrapping tightly around his waist, driving him deeper, their frenzied movements drove them both closer to the brink. "Fuck Fionna…you're so…AHH…tight, Mmm, yes…like that…" Fionna bucked her hips, meeting his cock thrust by thrust, their sweat mingling, bodies slipping together. The room filled with sounds of their moans, pants and squeals, as they indulged in their carnal desires for the first time.

"Oh Glob Marshall, don't stop PLEASE, harder, uggghhnnhh…" Fionna gripped Marshall's hair in one hand and the sheets in the other, feeling the warm throbbing of his member buried deep inside of her, stroking parts of her she didn't know existed. The feelings were almost too intense for her, pleasure wracking her body. She felt as though her entire body was pulsating with electricity, and her core radiated with a strange, powerful feeling, as though a tight coil were to spring at any second and send her over the edge. Her breasts bounced against his chest, nipples grazing his toned chest, and he panted hoarsely in her ear, slowly coaxing her and whispering her name in ecstasy. "That's it Fionna, let yourself feel my cock buried in you, MMmm.." His voice rang sensually in her ear, pushing her over the edge with a forceful thrust of his hips. She screamed, lips latching onto his in a forceful kiss, walls clenching around his engorged flesh, milking him, squeezing him, begging him to fall off the edge with her. His breathing was jagged and he knew he was close. "Fi, I'm gonna…uh…FIONNAAaa" His words were lost as Fionna gripped his back tightly with her legs, sheathing his entire cock in her aching core, his hair clinging to his forehead, his mouth open in a silent scream as she felt warm, thick liquid coat her inner walls.

Marshall collapsed on Fionna, taking care to not crush her under his weight, both of them panting heavily, struggling to catch their breath. His lips brushed her ear and she sighed in contentment, absentmindedly running a finger over the planes of his back, relishing in the tingling afterglow and dull ache between her legs. Moonlight shone through the window, and their breathing had returned to normal, both of them struggling to find the words to say.

"Wow…." Fionna uttered for the second time that day.

"Wow, yourself," Marshall chuckled. She weakly socked him in the arm before lovingly brushing a strand of his dark hair out of his eyes. He leaned into her touch. Then his eyes shot open and he cocked an eyebrow at her.

"Hey Fi, you know what I just realized?" Fionna looked at Marshall expectedly.

"We still need to pick those strawberries."


End file.
